October 31, 2008

Bats Die From Fungus

A nasty fungus is killing hundreds of thousands of bats in the northeastern United States, scientists said Thursday.

The previously unknown fungus thrives in chilly temperatures.

It's a white, powdery-looking organism found on the muzzles, ears and wings of dead and dying bats hibernating in caves in New York, Maine, Vermont and Connecticut.

The study was published in the journal Nature.

"Essentially, hibernating bats are getting moldy as they hang from their cave ceiling," David Blehert, a microbiologist with the U.S. Geological Survey said.
"It's decimating the cave-bat populations," he added.

Bats are an important element of the food chain. They keep down insect populations, pollinate plants and spread plant seeds.

Blehert said the disease is hurting all six species of hibernating cave bats in the northeastern United States. The species include little brown bats, big brown bats, northern bats, tri-colored bats, Indiana bats and the small-footed myotis.

At least 100,000 and maybe as many as 200,000 bats have died since the white-nose syndrome linked to the fungus first appeared in the winter of 2006-2007, he said.

Migratory tree bats, which live in the same region but fly to warmer locales in the winter rather than hibernating in caves, have not been affected, Blehert added.

The findings show the disease may be killing off more than 75 percent of the winged mammals as they hibernate.

The culprit may be a species of the fungi genus Geomyces, which is present in soil and eats organic matter.

The scientists have not yet determined if this fungus is the only factor in the bat deaths, because the bats also are emaciated.

Researchers are trying to understand if the disease came about because the fungus was introduced into the caves, or whether it just began harming bats after the animals were weakened by some other unknown cause.


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